I've spent a lot of my career working in the juvenile justice system. A few observations...
In 25+ years, I have yet to see a reporter get things corrected in a story involving a kid. One way or the other, they seem to neglect facts for the emotion of the story.
In 25+ years, I have never seen a child under the age of 12 arrested and transported for a non-violent offense. And I mean real violent act, not some BS threatening drawing kind of thing.
Different states have different laws regarding juvenile suspects. Some require a parent or other suitable adult to be present for any questioning. Some require an attorney be present. So, it may be legal in Hawaii.
Final observation, I have yet to meet a cop who would spend four hours on what appears to be no more than a scared straight session. Not likely.